Suchergebnisse

AbstractIn this short article, we respond to a Commentary by Maack et al. (Environ Sci Eur 34:24, 2022) in which they challenge recommendations in Leverett et al. (Environ Sci Eur 33:133, 2021) for setting an aquatic Environmental Quality Standard (EQS) for the pharmaceutical diclofenac. Maack et al. recommend the use of results from a stream mesocosm study as the main point of departure for setting the EQS and dismiss the use of a Species Sensitivity Distribution (SSD) containing relevant and reliable single species data because of bimodality in this distribution. We present the key mesocosm data used by Maack et al. and note that these are highly variable, include control mortalities of up to 60%, and, as reported by the original authors, show a significant effect only at the highest test concentration and not at the estimated value proposed by Maack et al. We also show that there are neither regulatory nor technical grounds for dismissing the use of an SSD and respond to minor criticisms of our compliance assessment (comparison of different EQS values with reported concentrations in European surface waters). Finally, we provide comment on the EQS derivation process and subsequent opinion of the diclofenac EQS dossier by the European Commission's Scientific Committee on Health, Environmental and Emerging Risks (SCHEER).

AbstractDiclofenac is a nonsteroidal anti-inflammatory human and veterinary medicine widely detected in European surface waters, especially downstream from Wastewater Treatment Plants (WWTPs). Veterinary uses of diclofenac in Europe are greatly restricted, so wastewater is the key exposure route for wildlife. Proposed Environmental Quality Standards (EQS) which include an assessment of toxicity to aquatic organisms are under consideration by the European Commission (EC) to support the aims of the Water Framework Directive (WFD). The EC approach favours the use of a deterministic (single test value and an assessment factor) approach to the derivation of a direct toxicity EQS for diclofenac, resulting in an EQS of 0.040 µg L−1 based on a single mesocosm study. In this paper, we discuss potential issues with this approach with respect to the EC's own guidance on EQS derivation and derive an evidence-driven alternative EQS of 0.126 µg L−1 using a probabilistic (species sensitivity distribution) approach that accounts for all of the reliable and relevant data and is in accordance with the guidance. Europe-wide freshwater monitoring data for diclofenac are used in an indicative compliance assessment using the EC and the alternative evidence-driven EQS. The implications of using only some data to derive an EQS that does not adhere to the guidance, compared to a guidance-compliant approach that uses all the data available are also discussed.